1. Field of the Invention
The present invention relates, in general, to an apparatus for being positioned between the outer circumference of an expandable mandrel and the inner circumference of a roll of sheet material.
2. Description of the Related Art
Many processing operations require that rolls or coils of strip material, such as sheet steel aluminum, be rotatably supported as the material enters and/or leaves a processing operation. Such coils are commonly supported on stub axles having expandable mandrels which can be contracted to allow a coil of material to be easily inserted or removed from the axle and which can be expanded to firmly grip the coil of material. If the inner diameter of the center aperture or eye of the coil of material is larger than the maximum expansion of the mandrel, it will be impossible to firmly secure the coil to the axle using the expandable mandrel alone. The prior art solution to such a problem is to provide a flexible elastomer tube for being inserted between the mandrel and the eye of the coil to act as a spacer or adaptor between the mandrel and the eye of the coil. A major disadvantage to such a spacer tube is the difficulty of handling such a flexible tube when positioning the tube on the mandrel or removing the tube from the mandrel, especially since the elastomer construction results in a somewhat floppy component, and the size of the elements involved commonly results in a spacer tube weighing between 500 and 600 pounds that normally requires a fork lift or the like to handle and that is extremely difficult to handle when floppy. Another problem that occurs when using such neoprene spacer tubes is that since the typical expandable mandrel includes only a relative few "segments" that define the outer circumference of the mandrel, when these segments are fully expanded, there is a considerable gap between adjacent segments which will cause the neoprene sleeve to deform from a circular shape thereby causing the coil of material to also deform from a circular shape when only a relatively small amount of the material remains on the coil.
A preliminary patentability search conducted in class 242, subclasses 72 R and 110.1 disclosed the following patents: Morton, U.S. Pat. No. 1,116,608; Steuer et al., U.S. Pat. No. 1,895,427; McLaughlin, U.S. Pat. No. 2,325,001; Tidland, U.S. Pat. No. 2,950,071; Richel, U.S. Pat. No. 3,289,966; Cunningham et al., U.S. Pat. No. 3,544,016; and Kataoka, U.S. Pat. No. 4,496,114. None of the above patents disclosed or suggest the present invention.